The present invention relates to a sandwich type ski and a method for producing the same, and more particularly relates to production of an FRP sandwich type ski having a core of an enhanced resistance against concave warping by load application in use.
One typical sandwich type ski is made up of an elongated core sandwiched by a pair of elongated surface guards made of metal such as Al. Use of an isotropic material such as Al for the surface guards, however, minimizes elastic response of the ski, increases its weight and disenables user's free management in use despite its rather smooth sliding characteristics.
In an attempt to remove these demerits inherent to the metal ski, an FRP sandwich type ski has been proposed and gained expanded use in which an elongated core is sandwiched by a pair of elongated surface guards made of fiber reinforced plastics (generally called FRP).
In use of such an FRP sandwich type ski, load application on the binding located about the middle of its length tends to develop a warping in the lower sliding surface of the ski which is concave in the transversal direction of the ski and such concave warping is generally accompanied with formation of sharp edges on the lateral sides of the lower sliding surface. As is well known, presence of such sharp edges on the lower sliding surface seriously impairs smooth sliding of the ski.